disable Spotlight Suggestions

By default in iOS 8 and Mac OS X 10 (Yosemite), your search queries, usage AND YOUR LOCATION at time of query will now be sent to Apple.

To disable Spotlight Suggestions in iOS 8:

1) Disable Spotlight Suggestions in General

Settings -> General -> Spotlight Search

UNCHECK Spotlight Suggestions

UNCHECK Bing Web Results

i.e. deselect / turn off both Spotlight Suggestions and Bing Web Results

(Read "About Spotlight Suggestions and Privacy" on that screen)

2) Disable Location for Spotlight Suggestions in Privacy

Settings -> Privacy -> Location Services -> System Services

switch Spotlight Suggestions OFF

3) Disable Spotlight Suggestions in Safari

Settings -> Safari - Search

switch Spotlight Suggestions OFF

For technical details, see Tidbits - How Spotlight Suggestions Handles Privacy